This invention relates generally to an ink ribbon cartridge for use with a printer or facsimile machine and, more particularly, to a thermal ink ribbon cartridge having one piece expandable sideplates which eliminate hinged connections and are easier to load with ink ribbon. The invention provides for an ink ribbon cartridge which ensures proper, reliable mounting of an ink ribbon.
Generally an ink ribbon cartridge is used because of the simplicity of handling when a thermal printer is used to print on paper. However, when a thermal printer uses a large ink ribbon cartridge, it is uneconomical for the whole cartridge to be thrown away after use. To obviate this drawback, an ink ribbon alone is replaced. The ink ribbon typically includes a band-like sheath comprising a resin film with a layer of ink formed on one side and is wound around a pair of cardboard spools.
A prior art ink ribbon cartridge using this type of ink ribbon is constructed such that at the time of ink ribbon replacement, a cover is unhinged, the used ink ribbon is taken out, and four spindles are removed from notches in the cartridge housing and from ends of the spools. The housing includes covers over each of the spools which are attached to the frame of the housing by living hinges and are secured into place by snaps which engage the covers and the frames of the housing. The covers are formed of two semi-cylindrical portions. The covers are locked into place by the snaps after the spools have been installed into the housing. Subsequently, the ink ribbon cartridge is mounted into a printer or facsimile system.
It is desired to provide an ink ribbon cartridge which does not have hinge members or snap members and is easy to load and unload with replacement ink ribbon and spools. Accordingly, it is desirable to develop a new and improved ink ribbon cartridge which meets the above-state needs and others and provides better, more advantageous overall results.
Generally speaking, the present invention relates to an ink ribbon cartridge which has a one-piece sideplate for installing and removing ink ribbon and spools.
More particularly, the invention relates to an ink ribbon cartridge which has a one piece sideplate which is expandable to easily remove and install take-up and supply spools having ink ribbon attached thereto. Thus, there are no hinge members or lock snap features required to retain the spools and ink ribbon within the ink ribbon cartridge.
In particular, an ink cartridge includes an ink ribbon, first and second spools for holding the ribbon, and four spindles. A spindle is received within a respective opening in an end of the spools. The housing has a first portion and a second portion which receive the first and second spools. A pair of sideplates connect the first portion to the second portion. The sideplates expand to allow the spindles to be installed within aligned holes of the sideplates. The sideplates are spaced apart and are generally parallel to each other. The first portion and second portion each have semi-cylindrical members that at least partially cover the spools.
The housing is formed of thermoplastic material and is a one-piece construction. First and second portions of the housing each have wall members at opposite ends which are generally normal to a longitudinal axis of the portions. Each of the wall members has a hole or opening for receiving the spindles. The sideplates are selectively pulled in opposing directions from a first dimension between the sideplates to a second dimension which is slightly greater than the first dimension.
One advantage of the present invention is the provision of an ink ribbon cartridge having a one piece construction to minimize parts that is easy to manufacture.
Another advantage of the present invention is the provision of an ink ribbon cartridge that eliminates any hinge members or snap lock features and is easy to load and unload with ink ribbon and spools.
Yet another advantage of the present invention is the provision of an ink ribbon cartridge which provides better retention of take-up spools and supply spools within the ink cartridge housing.
Still other aspects and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description.